Pneumatic tool driven by pulsating air



June 12, 1923. 1,458,569'

K. A. T. BERG PNEUMATIC TOOL DRIVEN BY PULSATING AIR Filed Dec. 15. 1921 JKA :'.Ber Q Patented June 12, 1,923.

. wires states 1 use KARL ASSAR THEOIDOR BERG, F HOGAIIAS, SWEDEN. v

rNnUMArIorooL DRIVEN BY rutsarrue am.

Application filed December 15 1921. I Serial No. 522,610.

To all whom it may concern:

Be it known that I, KARL Assan Tnnonon Buns, a citizen of Sweden, residing at Hoganas, Sweden, have invented certain new and useful Improvements in or Relating to Pneumatic Tools Driven by l-ulsating Air, of which the following is a spec1-' fication.

This invention relates to improvements in m pneumatic tools driven by pulsating air. When such tools do not work during shorter intervals, they must be constructed in such a way that the pulsating air column is neutralized or 'suppresed in order to do away with. the oscillatingsuction and pres-,

sure periods as completely as possible. Hitherto for this result, when the piston striker has been driven beyond its work- 1ng position, some holes are uncovered in so the cylinder wall, whereby sofiample a communication with the atmosphere is obtained that the action on the piston striker almost ceases. In dustyWorking places, as for instance in stone drilling, stone cutting foun-,

5 and 6 the air passages and .7 groovesin the walls of the working cylinder. In the drawing four such grooves are shown, to though a greater or smaller number also may be used. These grooves reach from the lower edge of the cylinder to slightly beneath the upper edge of the piston striker 2, when the tool at is in its proper position, as shown in Fig. 1. In Fig. 2 the tool 4 is shown in its outmost position, in which it is kept by means of a. device not shown in the drawing when it is not working. In this case the piston striker 2 travels so far down that the grooves 7 connect the cylinder on both sides of the piston striker. The

difference of pressure is now almost nil and thus the piston striker stands still. By

in Fig. 1 the piston striker is' againbrought into play.

This arrangement of the grooves 7 effects that the piston striker can be brought out of work without introducing impure air into the working cylinder.

The-inlet Gin such tools must be provided" at a distance from the cylinder bot-' tom in such a way that the space above forms a compression chamber taking up. the energy of the piston and preventing.

the latterfrom striking the bottom at the same time as the pressure thus produced sends the piston back makingit again susceptible of the impulse of the vair c0lumn through the passages 5 and 6.

Having thus described my invention,

ea rear; met. 1 I I pushing the tool 4 into the position shown what I claim as new and desire to secure by Letters Patent is I I 1. In a pneumatic tool adapted to be driven by asingle pulsating air column producing alternatlng periods of pressure and Vacuum a cylinder having a single inlet only for said air column with the inlet located adjacent the rear end of the cylinder, and a. striking piston mounted for reciprocation within said'cylinder by said alternating pressure and vacuum. the walls of the cylinder being being provided at the forward end' with a. bypass without direct. communication with the pulsating air column, said bypass extending in both 'direc-f tlons beyond the striking piston when the latter is at its limit of stroke in non-working position and being continuously closed against. the working portion ofthe cylinder when the piston is operating upon the tool.

'2. In a. pneumatic tool adapted to be driven by a single pulsating air. column producing alternate periods of pressure and vacuum. a. cylinder having a single inlet through which said pressure and vacuum operates with'respect to the cylinder, and a striking piston mounted for reciprocation within saidcylinder and alternately subjected to the pressure and vacuum through said single inlet, said cylinder being formed with means whereby when said piston is Q l v 1,458,569

in a predetermined position in the cylinder In testimony whereof, I have signed my the opposite sides of said piston Will be name to this specification in the presence simultaneously subjected to the alternate of two subscribing Witnesses. pressureand vacuum, whereby the piston is KARL ASSAR THEODOR BERG.

5 held substantially stationary in the cylin- Witnesses:

der notwithstanding continuous operation ERNST Pnnsson, of the pulsating air column. G. PETERSON. 

